The heart is a hollow muscle that, through its rhythmical contraction, ensures the progress of blood through the vessels. It comprises four cavities. The right atrium and the left atrium arranged in the upper part of the heart; the right ventricle and the left ventricle arranged in the lower part.
The right ventricle is designed to receive blood coming from the right atrium and then eject it into the pulmonary artery. This forms a “lesser circuit” allowing for the blood to be sent to the lungs for reoxygenation.
The left ventricle retrieves the oxygenated blood from the lungs via the left atrium and then ejects it towards the aorta to bring oxygen to all of the tissues of the organism. This is the “greater circulation”, called systemic circulation.
Cardiac insufficiency (CI), the progressive inability of the heart to provide the blood flow necessary for an individual's metabolic needs during everyday life, is the second biggest cause of death in Western countries. The treatment of cardiac insufficiency, which consists of increasing the blood flow in a manner appropriate to the patient's needs, is not very effective with current techniques, and is extremely costly.
Document US2009/0024212 is known, describing a pump for the treatment of cardiac insufficiency due to the inactivity of the sigmoid valves of the heart. This pump has an elongated shape extending from the inside of the left ventricle to the inside of the aorta in such a way as to replace the function of the valves.
Document U.S. Pat. No. 6,217,541 is also known, describing a heart pump that is also inserted through the aorta to the inside of the ventricle. The end of the pump draws up the blood contained in the left ventricle and then transfers it to the aorta via a flexible channel integral with the end of the pump and arranged through the valves.
The pumps described above require complex installation, and are not designed for permanent use.
Document U.S. Pat. No. 6,234,772 is also known, describing an implantable rotary pump. This pump is magnetically driven and is used to force blood circulation, avoiding any stagnant zones. This document remains silent with regard to any efficient installation of the pump.
Document WO2010/010407 describes a rotary heart assist pump discharging the blood from the left ventricle through the aortic valve. This pump is fixed through the aortic valve with fasteners in the aorta and at the ventricular apex. The electric motor is located in the conduit passing through the aortic valve.
Finally, document US2005/0107657 is known, describing a left ventricular assist device (mixed-flow blood pump) with a so-called “radial” blood inlet circuit and a so-called “axial” blood outlet circuit by means of a rotative impeller located at the centre of the device. The base is held inside the left ventricular cavity by a semi-rigid rod through the apex of the ventricle, while the summit of the device passes through the aortic valve with functional modification or elimination of the valve. Surgically, a sternotomy with installation of a cardiopulmonary bypass is necessary, as an incision must be made in the aortic root. The electric motor is located inside the device, therefore inside the left ventricle. This document also discloses an optimum efficiency equation between the diameter of the pump and the number of revolutions per minute of the impeller (up to 11,000 rpm). The diameter of the pump is given as ˜20-22 mm.